Showing papers by "Ann M. Graybiel published in 2001"
TL;DR: It is suggested that neurons in the CM and Pf supplystriatal neurons with information about behaviorally significant sensory events that can activate conditional responses of striatal neurons in combination with dopamine-mediated nigrostriatal inputs having motivational value.
Abstract: The projection from the thalamic centre median–parafascicular (CM-Pf) complex to the caudate nucleus and putamen forms a massive striatal input system in primates. We examined the activity of 118 n...
424 citations
Journal Article•
70 citations
TL;DR: It is suggested that the CalDAG‐GEFs may be key intracellular regulators whereby calcium and diacylglycerol signals can regulate cellular functions through small GTPases in the basal ganglia circuits.
Abstract: CalDAG-GEFI and CalDAG-GEFII (identical to RasGRP) are novel, brain-enriched guanine nucleotide exchange factors (GEFs) that can be stimulated by calcium and diacylglycerol and that can activate small GTPases, including Ras and Rap1, molecules increasingly recognized as having signaling functions in neurons. Here, we show that CalDAG-GEFI and CalDAG-GEFII mRNAs, detected by in situ hybridization analysis, have sharply contrasting forebrain-predominant distributions in the mature brain: CalDAG-GEFI is expressed mainly in the striatum and olfactory structures and deep cortical layers, whereas CalDAG-GEFII is expressed widely in the forebrain. Within the striatum, however, the two CalDAG-GEF mRNAs have nearly identical distributions: they are coexpressed in striatal projection neurons that give rise to the direct and indirect pathways of the basal ganglia. Subcellular fractionation analysis of the substantia nigra with monoclonal antibodies against CalDAG-GEFI suggests that CalDAG-GEFI protein is present not only in the cell bodies of striatal projection neurons but also in their axons and axon terminals. These results suggest that the CalDAG-GEFs may be key intracellular regulators whereby calcium and diacylglycerol signals can regulate cellular functions through small GTPases in the basal ganglia circuits. J. Comp. Neurol. 437:398–407, 2001. © 2001 Wiley-Liss, Inc.
33 citations
TL;DR: It is suggested that the basal ganglia control cortical activity by pushing a local cortical network into a new attractor state, thereby selecting certain attractors over others.
30 citations
12 Dec 2001
TL;DR: The basal ganglia, composed of several groups of cells at the base of the cerebrum, plays an important role in the production of smoothly-linked behaviours.
Abstract: The basal ganglia, composed of several groups of cells at the base of the cerebrum, plays an important role in the production of smoothly-linked behaviours. The means by which information is modulated in the basal ganglia by neurotransmitters and neuromodulators released in response to expected reward and to specific motor commands is a topic of active investigation.
Keywords:
basal ganglia;
striatum;
globus pallidus;
dopamine
4 citations